Oil well pump



Feb. 23, 1943. H. J. PANKRATZ OIL WELL PUMP 4 2; Sheets-Sheet 1 Filed Dec. 6, 1941 INVENTOR HOWARD J. PA N KRATZ 1943- H. J. PANKRATZ OIL WELL PUMP Filed Dec. 6, 1941 2 Sheets-Sheet 2 INVENTOR HOWARD J. PANKR z v TTORN Patented Feb. 23, 1943 UNITED STATES.

PATENT OFFICE OIL WELL PUMP of Delaware Application December 6, 1941, Serial No. 421,985

4 Claims.

This invention relates to oil well pumps and more particularly to an oil well pump employing r gas pressure to lift the oil from the well.

An important object of the invention is to provide a pumping apparatus which may be located at the bottom of the well and having a cylinder means, which, by rotation imparted thereto from the surface of the ground, may alternately be connected with gas under pressure to force oil from an accumulation chamber of the pump and to close oil the gas pressure to allow the accumulation chamber to be exhausted of gas and to refill with oil.

A further object of the invention resides in its simplicity of design, the small number of working parts, economics of operation, and the fact that it provides for surface control of a bottom hole gas operated displacement pump.

. Another object of the invention is to provide an apparatus which is an improvement over gas 20 driven bottom hole pumps, such as the type disclosed in U. S. Patent 2,202,970 that issued June 4, 1940, to Francis E. Steele.

These and other objects and advantages will be apparent to persons skilled in the art by reference to the following description and annexed drawings, which pertain to a preferred embodiment of my instant invention, wherein:

Figure 1 is an elevation view oi the upper portion of my instant invention, partly in crosssection;

Figure 2 is an elevation view of the lower part of my instant invention, partly in cross section;

Figure 3 is a sectional view of my invention taken along line 3-4 of Figure 1; I

Figure 4 is a sectional view taken along line 4-4 ofFlgure i;- V

Figure 5 is also a sectional view taken along line 5-5 of Figure 1;

Figure 6 is another sectional view taken along line 6-5 oi Figure 1: and

Figure '7 is a sectional view of my instant invention taken along line of Figure 2.

Referring to the drawings and in particular to Figures 1 and 2, I have designated an outer string of oil well tubing by reference numeral 15. Tubing II, which is supported in a well bore from the surface of the ground in any known manner, is connected at its lower end to an adapter H which in turn is threadedly secured at its lower end to a barrel I2 in a manner which will be explained later along in this specification. The lower end of the barrel is connected to a valve member it, which is provided with a 55 50 ment.

check valve I4. The lower end of the valve mem her is preferably connected to a member l5, having perforations or openings l6 through which fluid from a well bore may enter thereinto. A second string of oil well tubing I1 is rotatably positioned in tubing l0, forming an annular:

space I8 which extends downwardly from the surface of the ground to the top of adapter ll. Tubing I 1 is supported at the surface of the 10 ground and rotated in any known manner. The

lower end oftubing ll contains an expansion coupling l9 which is adapted to facilitate the placing of my instant apparatus in an operating position. This expansion coupling includes an upper cylindrical member 20, which is provided with a central bore 2|. Referring also to Figure 3, it will be noted that member is adapted to slide within tubing H. Member 20 is threadediy connected to a stem 22 having a central passage 23 that connects with bore 2|. The external surface of stem 22, which is preferably hexagonal in cross-sectional shape, is spaced apart from the internal surface of tubing ll, forming a chamber 24 which is bounded at the top by the 25 lower end of member-20 and at the bottom by the upper end of an adapter collar 25 which is threadedly connected to the lower end of tubing ll. As also shown in Figure 4, collar 25 is provided with a central hexagonally shaped opening 25 which is adapted to permit substantially vertical movement between collar 25 and stem 22. It is to be understood that I do not desire to limit my instant invention by the shape of stem 22 and opening 26, rather stem 22 and opening 26 may be of any desired cross-sectional shape which will permit substantially vertical movement therebetween and which will allow collar 25 to impart rotational movement to stem 22 regardless of the position of the collar with respect to the surface of stem 22. A coiled spring 21, which is contained in chamber 24, prevents member 20 and collar 25 from coming together with appreciable impact during the running of tubing I! in or out of tubing in. The spring in functioning as a shock absorber slows down the movement of stem 22 through opening 28 and brings member 22 to rest more evenly and without producing an injurious impact load which would have a damaging eil'ect upon the equip- A cylinder, which is generally referred to by reference numeral 28, is positioned in adapter I l by a plurality of sealing rings 28 which are provided on the external surface of a barrel 80. The barrel has a plurality of aerating ports 3| which connect with annular space I8, a gas inlet part 32 which also communicatesmith the annular space, and a plurality of exhaust ports 33 which communicate with the exterior of my device by way of a circular passage 34 and radial passages 35, which are provided in adapter II. It is to be understood that although I have shown a plurality of ports 33, that the ports function as one port. Like ports 3i function a a single port. I prefer to use a plurality. of ports 3| and 33 because this type of construction makes my device stronger and more durable. A radialthrust bearing 35 which is positioned near the top of cylinder 28 upon a pair of flush flanges 31 and 38, that are provided respectively on the internal surface of the upper portion of barrel 30 and on the external surface of a rotatable valve member 39. The bearing is held in place upon the flanges by an externally threaded ring 40 and an internally threaded ring 4i. Ring 40,

the lower portion of which is threadedly connected to the upper end of barrel 30, and ring 4|, the lower end of which is threadedly connected to the upper end of valve member 33 and the upper end' of which is threadedly connected to the lower end of stem 22, are spaced in relationship that permits stem 22, ring 4|, and valve member 39 to freely rotate while barrel 30 re mains in a non-rotative position. It is to be noted that valve member 39 is provided with a vertical passage 42 which provides communication between central passage 23 and a conduit 43, and with a radial passage 44. The upper end of conduit 43 is externally threaded to connect with the lower end of the valve member. A rotatable tubular valve 45 is also threadedly connected to the lower end of the valve member in a manner whereby the inner surface of the tubular valve is spaced apart from the outer surface of conduit 43, forming a space 46 which for purposes of this description is to be understood as that space which is exterior to conduit 43 and which extends downwardly from the lower end of the valve member through cylinder 28 to connect with an accumulation chamber 41 that is formed interior to barrel I2. Tubular valve 45 is provided with an opening 43 that permits communication between passage 44 and aerating port 3|, with an inlet opening 43 that permits communicating between space 48 and inlet 32, and with an exhaust opening 50 that permits communication between space 48 and exhaust ports 33. Referring to Figures 5, 6, and 7, it will be noted that tubular valve 45 is in a position whereby inlet port 32 is placed in alignment with opening 49, permitting communication between space 48 and annular space l8 and whereby ports 3! and 33 are out of alignment with openings 48 and 50, respectively. By rotating the tubular valve to a position in which ports 3| and 33 are brought into alignment with openings 48-and 50, respectively, port 32 does not align with opening 49. In thisposition, annular space l8 communicates with passage 42 through ports 3|, opening lower portion of accumulation chamber 41, is secured at the top to the lower end of cage 54.

In operation, my instant apparatu is assembled, as shown in the drawings, and positioned in a well bore. It is to be understood that collar 25 may be positioned along stem 22 at any desired place, which is determined by the operating conditions to which my device is subjected, such as changes in temperatures which will cause tubing I1 to become longer or shorter. For example, if the temperature of the fluids passing along the tubing during the operation of my apparatus is such that tubing l1 will contract appreciably, collar 25 is positioned near the lower end of stem 22. On the other hand, if tubing will be caused to lengthen appreciably during the operation of my device, collar 25 may be placed near the upper end of stem 22. In addition to the above use, expansion coupling l9 also serves as a shock absorber. For example, during the running" of tubing I1 in tubing l0, tubing 11 is usually brought to an abrupt stop as new joints of tubing are added to the tubing string. However, stem 22 will continue to move downwardly until the lower end of member 20 engages the top of spring 21. As the bottom of the spring rests upon the top of collar 25, the spring is compressed bringing stem 22 to rest more evenly and thereby preventing severe impact loads from occurring in tubing l1 and in other parts of my device. It will be apparent that expansion coupling i9 provides a means for operatively positioning cylinder 28 within adapter ii. After my apparatus is positioned, tubing 11 is rotated in a clockwise direction from the surface of the ground by any means which is known in the art. High pressure gas or air is injected into annular space ii! at the surface of the ground, and fluid from the bottom of a well bore flows through perforations I6 and thence upwardly past valve I4 to the top of accumulation chamber 41. When the various parts of my apparatus are in a position, as shown in the drawings, gas from annular space l8 flows through passage 32, opening 49, and thence into space 46 from which the gas enters accumulation chamber 41 and exerts a pressure upon the well fluid therein, causing valve M to be closed and causing the well fluid to flow upwardly through tube 56, past check valve 55, thence through cage member 54, conduit 43, vertical passage 42, central passage 23, bore 2 I, and finally upwardly through inner tubing H to the surface of the ground. Tubing I1 is rotated from the surface of the ground at a speed which will permit the high pressure gas from annular space 18 to substantially remove all of the well fluid previously admitted into chamber 41. It is to be noted that the high pressure gas is permitted to flow from the annular space to the accumulation chamber during a comparatively short time interval. This per- I mits the gas in space 46 and chamber 41 to ex- 48, and passage 44;.and space 45 communicates with the exterior of my instant device by way of opening 50, ports 33,,circu1a1fjpassage 34, and radial passages 35. 'Referring in particular to Figure 2, it is to be noted that adapter H is preferablyattachedto barrel 12 by means of coupling 5! having a seating fla'ngefi, that is adapted to accommodate a seating nippieflwhich is threadedly. attached .to thelower .end of barrel 30. The lowerend of conduit{, 43 ,is attached to a cage member 54 whicltc'arrlesa check valve member 55. A-tubeEB, whichextends downwardly to the pand more fully and thus effect a more efilcient lifting of the well fluid to the surface of the ground. When suificient time has lapsed for the pressured gas to remove the well fluid from the accumulation chamber, the tubular valve will have rotated sufficiently to align one of the ports 33 with opening 60, permitting the gas in the accumulation chamber to escape therefrom by way of ports 33, opening 50, circular passage 34, and thence through radiallports 35 to the exterior of my device. The accumulation chamber is in communication with the exterior of my device during a major portion of the time required for one revolution of tubular valve 45, allowing the pressure gas to be exhausted from the accumulation and permitting the chamber to again flll with well fluid. At the sametime as the gas starts to exhaust from the accumulation chamber, passage 44 and opening 48 are brought into alignment with one of the ports 3|. This permits high pressure gas in annular space 18 to flow through ports 3|, opening 48, passage 44, and thence into vertical passage 42 where the high pressure gas enters the fluid column flowing upwardly from the accumulation chamber and assists in lifting the fluid upwardly to the surface of the ground. As the accumulation chamber is exhausting to the exterior of the apparatus, the pressure of the fluid column above check valve 55 will be greater than the pressure,

therebeneath, due to the weight of the column of fluid and the pressure of the gas acting on the column of fluid, causing the valve to close and thus prevent fluid in conductor 43 from flowing downwardly into the accumulation chamber. It is to be noted that high pressure gas enters the column of fluid flowing upwardly to the surface of the ground during a major portion of the pumping cyclewhich is repeated once for each revolution of tubular valve 45, while during the remaining portion of the pumping cycle, the fluid in accumulation chamber 41 enters the fluid col umn. The intermittent entering of gas and well fluid into the fluid column causes the well fluid to be dispersed in the fluid column in the form of fluid slugs which are separated by slugs of gas. The slugs of gas in effect are gas pistons which I ico'ntinuously urge the well fluid to the surface of the ground. As the gas pistonsf near the surface of the ground, the gas expands due to the lightened weight of the fluid thereupon and utiilzes the energy stored in the gas by compression to further assist in lifting'the fluid column to the surface of the ground. It will be apparent that the gas which enters tubing H by way of ports 3|, opening 68, passage 44, passage 42, passage 23, and bore 2| in addition to lessening the weight'or the fluid column, prevents the column from coming to rest during each pumping cycle.

Therefore, I am able to use gas which is compressed to a lesser amount than could be used if the fluid column were allowed to come to rest at the end of each pumping cycle.

From the foregoing, it is believed that the construction, operation, and advantages of my present invention will be readily comprehended by persons skilled in the art. It is to be clearly understood, however, that various changes in the apparatus may be resorted to without departing from the spirit of the invention, as defined by the appended claims.-

I claim:

1. In a well pumping apparatus of the class described, the combination comprising an outer tubing for transmitting gas under pressure into a well bore; a rotatable inner tubing for withdrawing fluid from the well bore, said inner tubing being within the outer tubing and spaced therefrom to form an annular passage therewith; partitioning means for dividing the annular passage into an upper annular passage and a lower annular passage, said partitionin means including a cylinder associated with both the inner and outer tubing, means for supporting the cylinder within the outer tubing, a plurality of ports in the cylinder, one of saidports communicating with the exterior of the outer communicating" tubing, and a pair of said ports with the upper annular passage; a pair of substantially concentric conduits rotatable within the cylinder upon rotation of the inner tubing and spaced from each other to form an annulus which extends downwardly from a point intermediate the said pair of ports in the cylinder and which communicates with the lower annular passage, said pair of conduits including an inner conduit constituting a part of the inner tubing and an outer ported conduit adapted to periodically communicate with the above mentioned ports in the cylinder upon rotation of the inner tubing; valve means for controlling the admission of well fluid into the lower annular passage; and check valve means in the inner tubing for controlling the flow of well fluid from the lower annular passage through the inner tubing.

21in a well pumping apparatus of the class and a lower annular passage, said partitioning means including a cylinder associated with both the inner and outer tubing, means for supporting the cylinder within the outer tubing, a plurality of passages in the cylinder, one of said passages communicating with the exterior of the outer tubing, and a pair of said passages communicating with the upper annular passage; a pair of substantially concentric conduits rotatable within the cylinder upon rotation of the inner tubing and spaced from each other to form an annulus which extends downwardly from a point intermediate the said pair of passages in the cylinder and which communicates with the lower annular passage, said pair of conduits ineluding an inner conduit constituting a part of the inner tubing and an outer conduit comprising a port which periodically communicates with one of the said pair of passages in the cylinder for controlling the flow of gas from the upper annular passage into the lower annular passage during a portion of the pumping cycle, a second port which periodically communicates with the first passage in the cylinder for controlling the flow oigas from the lower annular passage to the, exterior of the outer tubing during a portion of the pumping cycle other than the first mentioned portion, and'a third port which periodically communicates with the other of the said pair of passages in the cylinder for controllin the transmission of gas from the upper annular passage into the inner tubing during the second mentioned portion of the pumping cycle; valve means for controlling the admission of well fluid into the lower annular passage; and check valve means in the inner tubing for controlling the flow of well fluid from the lower annular passage through the inner tubing.

3. In a well pumping apparatus of the class described, the combination comprising an outer tubing for transmitting gas under pressure into a well bore; a rotatable inner tubing for with drawing fluid from the well bore, said inner tubing being within the outer tubing and spaced therefrom to form an annular passage therewith; partitioning means for dividing the annular passage into an upper annular passage the inner and outer tubing, means for supporting the cylinder within the outer tubing, a plurality of ports in. the cylinder, one of said ports communicating with the exterior of the outer tubing, and a pair of said ports communicating with the upper annular passage; a pair of substantially concentric conduits rotatable within the cylinder upon rotation of the inner tubing and spaced from each other to form an annulus which extends downwardly from a point intermediate the said pair of ports in the cylinder and which communicates with the lower annular passage, said pair of conduits including an inner conduit constituting a part of the inner tubing and an outer ported conduit adapted to periodically communicate with the exterior of the cylinder; a radial-thrust bearing associated with both the inner tubing and the partitioning means for aligning the pair of rotatable conduits with the cylinder and for positioning the conduits within the cylinder; valve means for controlling the admission of well fluid into the lower annular passage; and check valve means in the inner tubing for controlling the flow of well fluid from the lower annular passage through the inner tubing.

4. In a well pumping apparatus of the class described, the combination comprising an outer tubing for transmitting gas under pressure into a well bore; a rotatable inner tubing for withdrawing fluid from the well bore, said inner tubing being within the outer tubing and spaced therefrom to form an annular passage therewith;

partitioning means for dividing the annular' passage into an upper annular passage and a lower annular passage, said partitioning means including a cylinder associated with both the inner and outer tubing, means for supporting the cylinder within the outer tubing, a plurality of passages in the cylinder, one of said passages communicating with the exterior of the outer tubing, and a pair of said passages communicating with the upper annular passage; a pair of substantially concentric conduits rotatable within the cylinder upon rotation of the inner tubin and spaced from each other to form an annulus which extends downwardly from a point intermediate the said pair of passages in the cylinder and which communicates with the lower annular passage, said pair of conduits including an inner conduit constituting a part of the inner tubing and an outer conduit comprising a port which periodically communicates with one of the said pair of passages in the cylinder for controlling the flow of gas from the upper annular passage into the lower annular passage during a portion of the pumping cycle, a second port which periodically communicates with the first mentioned passage in the cylinder for controlling the flow of gas from the lower annular passage to the exterior of the outer tubing during a portion of the pumping cycle other than the first mentioned portion, and a third port which periodically communicates with the other of the said pair of passages in the cylinder for controlling the transmission of gas from the upper annular passage into the inner tubing during the second mentioned portion of the pumping cycle; a radial-thrust bearing associated with both the inner tubing and the partitioning means for aligning the pair of rotatable conduits with the cylinder and for positioning the conduits within thecylinder; valve means for controlling the admission of well fluid into the lower annular passage; and check valve means in the inner tubing for controlling the flow of well fluid from the lower annular passage through the inner tubing; and shock absorbing extensible means for operatively attaching the inner tubing to the pair of rotatable conduits.

HOWARD J. PANKRATZ. 

